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Chapter 5 CPP Study Questions

Ch 5 Exposure

Q1) An incident exposure reading for a fair skinned subject indicates f8, 1/125 at ISO 100. The next client is very dark skinned. The proper exposure for this client at the same subject position is thus:

Q1: D
Q2: B
Q3: This one makes me feel stupid. I can't wrap my brain around the 3 different variables, without one constant. I can do it with 2 variables, but I can't with 3. I even made charts and none of them matched up. Whyyyyy??? Am I trying too hard??

Q1. I note that we're taking an incident reading, but the term "subject failure" (a misnomer, but that's the "common" term) comes to mind. This one will call for discussion.

I am torn between having that discussion here or elsewhere. If we have it here, it's relevant, but will it detract from those studying and practicing? This is one of the questions I believe I answered incorrectly on my actual exam.

Kirk, can you define "Subject failure"? I've never heard of it - I googled and came up with nothing.

Well, an incident meter tells you how to properly expose a gray card. That works for any subject that is within a stop or two of middle gray for all the subject tones you want to capture detail in.

But what if the subject is wholly within the upper end of the range, such as white lace on white satin--and you want to retain the fabric texture even in the highlights? Or what if you're shooting a black Labrador and you want to maintain some detail of the dog's coat even in the shadows?

In that case, the middle-range incident measurement may fail to give you what you want (it's actually "measurement failure," but people have called it "subject failure"). In those cases, you may have to change some factor to get the range you want.

It might be exposure--you may have to decrease the incident setting to keep all of a totally high-end scene within the range of your materials, or you may have to increase exposure to keep all of a totally low-end scene within range. Or you may be able to change the subject lighting--specifically lower the contrast in some way.

If there was some need to keep the background identical between clients (such as with school photography), then you'd change the lighting, not the exposure.

The concept of this question is that because the reflectance of the subject doesn't change the incident reading, the exposure wouldn't change. But in the real world where some subjects are far from middle gray...it might.

--Elephants can swim......and very gracefully. Knowing that, I do believe Anything is possible for me.